If you have installed an FPC that houses one or more PICs, the PICs function only after you add the necessary statements for them to the router configuration. For instructions, see the JUNOS Network Interfaces Configuration Guide. If you have installed a blank FPC panel or a blank PIC, you do not need to modify the configuration of the router. The router automatically discovers that the interfaces in an FPC slot or PIC location are nonoperational and does not attempt to initialize them.